[PATCH AUTOSEL 4.19 03/83] pvcalls-front: read all data before closing the connection

Sasha Levin
2019-02-13T02:57:31Z

From: Stefano Stabellini <sstabellini@kernel.org>

[ Upstream commit b79470b64fa9266948d1ce8d825ced94c4f63293 ]

When a connection is closing in_error is set to ENOTCONN. There could
still be outstanding data on the ring left by the backend. Before
closing the connection on the frontend side, drain the ring.

Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/xen/pvcalls-front.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 77224d8f3e6f..e5d95aab2cb8 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -560,15 +560,13 @@ static int __read_ring(struct pvcalls_data_intf *intf,
error = intf->in_error;
/* get pointers before reading from the ring */
virt_rmb();
- if (error < 0)
- return error;

size = pvcalls_queued(prod, cons, array_size);
masked_prod = pvcalls_mask(prod, array_size);
masked_cons = pvcalls_mask(cons, array_size);

if (size == 0)
- return 0;
+ return error ?: size;

if (len > size)
len = size;
--
2.19.1